Resistance regulator for a magnetic brake

ABSTRACT

A resistance regulator for a magnetic brake includes a resistance-designating mark unit and an indicator, which can rotate relative to each other so as to move a pull rope that is adapted to be connected to the brake. The mark unit has a small-resistance mark and a plurality of equidistant large-resistance marks. The indicator is directed toward a selected one of the large-resistance and small-resistance marks. Each adjacent pair of the large-resistance marks are spaced apart from each other at a distance that is smaller than the distance between the small-resistance mark and a leading one of the large-resistance marks.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a resistance regulator, moreparticularly to a resistance regulator, which is connected to a magneticbrake by means of a pull rope that can move so as to adjust themagnitude of the resistance applied by the brake.

[0003] 2. Description of the Related Art

[0004] Referring to FIGS. 1 and 2, a conventional flywheel brakeassembly for an exercise bike is shown to include a wheel shaft 1, and aflywheel 2 disposed fixedly around the wheel shaft 1 and disposedrotatably within a housing 2′. An aluminum ring 3 is fixed in thehousing 2′. Two mounting plates 4 have upper ends 4′ that are mountedpivotally in the housing 2′ such that the mounting plates 4 can turntoward or away from each other. Each of the mounting plates 4 isprovided with a plurality of fixed magnets 5 (only two are shown), andis biased by a spring 6, which is confined between the aluminum ring 3and the respective mounting plate 4, to a position so that the magnets 5are adjacent to an inner surface of the flywheel 2. Accordingly, themagnets 5 attract the flywheel 2 so as to provide a resistance torotation of the flywheel 2, thereby functioning as a magnetic brake.When it is desired to reduce the resistance to the rotation of theflywheel 2, a pull rope 14 is drawn so as to move a movable piece 7radially and inwardly in a radial slot 8 in the housing 2′ such that themounting plates 4 rotate toward each other, thereby increasing thedistance between the flywheel 2 and the magnets 5. When it is desired toincrease the resistance to the rotation of the flywheel 2, the pull rope14 is operated such that the magnets 5 are biased by the springs 6 tomove toward the inner surface of the flywheel 2, thereby reducing thedistance between the magnets 5 and the flywheel 2. FIG. 3 shows aconventional resistance regulator 10 for operating the pull rope 14,which includes an upper casing 11, a lower casing 12 that is connectedfixedly to the upper casing 11, a vertical rotating shaft 13 journalledon the lower casing 12, and a reel 13′ sleeved non-rotatably on therotating shaft 13. The pull rope 14 is wound around the reel 13′, andhas one end that is fastened to the reel 13′, and another end that iscoupled with the brake assembly such that the springs 6 (see FIG. 1)bias the pull rope 14 to unwind from the reel 13′. A rotary knob 15 isconnected fixedly to the rotating shaft 13 so that rotation of therotary knob 15 results in winding or unwinding of the pull rope 14relative to the reel 13′. An indexing disc 161 is sleeved fixedly on therotating shaft 13, and has an outer periphery with a serrated annularflange 164 that projects integrally and upwardly and that defines aplurality of positioning grooves 164′. A movable plate 162 is disposedmovably relative to the upper and lower casings 11, 12, and is biased tomove downwardly by a spring 163 so as to engage a downwardly extendingintegral tongue 165 of the movable plate 162 with a selected one of thepositioning grooves 164′, thereby determining the magnitude of theresistance. As such, the magnets 5 (see FIGS. 1 and 2) can move towardthe inner surface of the flywheel 2 (see FIGS. 1 and 2) step by step. Toindicate the magnitude of the resistance, the resistance regulator 10further includes a rotary disc 17 and a fixed disc 17′. The rotary disc17 is sleeved fixedly on the rotating shaft 13, and has acircumferential face that is marked with six equidistant numerals “1” to“6”. The fixed disc 17′ is fixed on the lower casing 12, and has a topsurface that is marked with six equidistant numerals “1” to “6”. Arotary knob 15 can be rotated about the fixed disc 17′ so that atriangular indicator 151 of the rotary knob 15 is aligned with aselected one of the numerals “1” to “6” on the fixed disc 17′. As such,the rotary disc 17 rotates relative to the upper casing 11 to aposition, where a triangular indicator 111 of the upper casing 11 isaligned with a corresponding one of the numerals “1” to “6” on therotary knob 17. The numerals “1” on the rotary disc 17 and the fixeddisc 17′ represent zero resistance that means no magnetic attractiveforce is produced between the flywheel 2 (see FIG. 1) and the magnets 5(see FIG. 1).

[0005] In a situation where the manufacturing precision of the brakeassembly is comparatively low, it is likely that when the rotary knob 15is rotated to a position, where the indicators 111, 151 are aligned withthe numerals “2”, “3”, or even “4”, the brake assembly is still disposedat a zero resistance state. When the rotary knob 15 is rotated to movethe top and side indicators 151, 11 between any adjacent pair of thenumerals “1”, “2”, “3”, “4”, “5”, “6”, the magnets 5 (see FIGS. 1 and 2)move a constant small distance (L) (see FIG. 2). As a result, when thebrake assembly is associated with the aforesaid resistance regulator 10,there is a need for a relatively high precision during manufacture andassembly of the magnetic brake in order to maintain effective adjustmentof the regulator 10. Furthermore, it is difficult to read the numerals“1” to “6” for selection during resistance adjustment.

SUMMARY OF THE INVENTION

[0006] An object of this invention is to provide a resistance regulatorwhich is connected to a magnetic brake by means of a pull rope and whichhas a resistance-designating mark unit and an indicator that cooperatewith each other so that the regulator can adjusted effectively even ifthe manufacturing precision of the brake is comparatively low.

[0007] Another object of this invention is to provide a resistanceregulator with a resistance-designating mark unit and an indicator,which cooperate with each other so that a selectedresistance-designating mark can be read easily.

[0008] According to this invention, a resistance regulator for amagnetic brake includes a resistance-designating mark unit and anindicator, which can rotate relative to each other so as to move a pullrope that is adapted to be connected to the brake. The mark unit has asmall-resistance mark and a plurality of equidistant large-resistancemarks. The indicator is directed toward a selected one of thelarge-resistance and small-resistance marks. Each adjacent pair of thelarge-resistance marks are spaced apart from each other at a distancethat is smaller than the distance between the small-resistance mark anda leading one of the large-resistance marks. As such, there is no needfor high precision during the manufacture and assembly of the brake inorder to maintain effective adjustment of the regulator.

[0009] In one preferred embodiment, the indicator is configured as avertical line unit which is defined between a light-colored area and adeep-colored area of an outer surface of a rotary ring that is disposedrotatably on a base. The mark unit is formed on an outer surface of asurrounding wall of a cylindrical regulator body, which is fixed on thebase. The surrounding wall is disposed around the rotary ring, and isformed with an elongated circumferentially extending window, withinwhich the vertical line unit is visible. Because the deep-colored areais conspicuous in the window so that the vertical line unit can be seenclearly, the selected one of the large-resistance and small-resistancemarks that is aligned with the vertical line unit can be read easily,thereby facilitating efficient adjustment of the resistance regulator.Alternatively, the mark unit can be formed from a white colorant, and isindicated on a transparent shield, which is fixed to the surroundingwall and which covers the window. Because the white mark unit isconspicuous in the deep-colored area, it can also be read easily.

[0010] In another preferred embodiment, the indicator is configured as adark-colored area that is disposed between two light-colored areas andthat is sized so that only a selected one of the large-resistance andsmallresistance marks can be disposed therein. The darkcolored area isformed on an outer surface of a rotary ring which is disposed rotatablyon a base and which is disposed within a surrounding wall of acylindrical regulator body that is fixed on the base. The surroundingwall includes an elongated circumferentially extending window, withinwhich the dark-colored area is movable, and a fixed transparent shieldthat covers the window. The mark unit is indicated on the shield, and isformed from a white colorant. As such, because the white colorant isconspicuous within the dark-colored area, it can be discerned easily.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] These and other features and advantages of this invention willbecome apparent in the following detailed description of the preferredembodiments of this invention with reference to the accompanyingdrawings, in which:

[0012]FIG. 1 is a schematic side view of a conventional flywheel brakeassembly for an exercise bike, which is provided with a magnetic brake;

[0013]FIG. 2 is a sectional view of the conventional flywheel brakeassembly;

[0014]FIG. 3 is an exploded perspective view of a conventionalresistance regulator for the magnetic brake;

[0015]FIG. 4 is an exploded perspective view of a first preferredembodiment of a resistance regulator for a magnetic brake according tothis invention;

[0016]FIG. 5 is a fragmentary sectional view of the first preferredembodiment, illustrating the relationships among a base, a hollowrotating shaft unit, and a cylindrical regulator body of the firstpreferred embodiment;

[0017]FIG. 6 is a fragmentary sectional view of the first preferredembodiment, illustrating a connection between a rotary knob and the baseand a connection between the rotary knob and a rotary cap;

[0018]FIG. 7 is a top view of a ring plate of the first preferredembodiment, illustrating angular intervals of a plurality of positioningunits;

[0019]FIG. 8 is a sectional view of a flywheel brake assembly, which isassociated with the first preferred embodiment, illustrating how severalmagnets are moved toward a flywheel step by step;

[0020]FIG. 9 is a front view of the first preferred embodiment,illustrating the cooperation between a resistance-designating side markunit and a side indicator which is configured as a vertical line unitthat is movable within a window;

[0021]FIG. 10 is a view similar to FIG. 9, illustrating longitudinalmovement of the vertical line unit in the window;

[0022]FIG. 11 is an assembled perspective view of the first preferredembodiment, illustrating the arrangement of a resistance-designating topmark unit with respect to a top indicator;

[0023]FIG. 12 is another assembled perspective view of the firstpreferred embodiment, illustrating the arrangement of the side mark unitwith respect to the side indicator;

[0024]FIG. 13 is an assembled perspective view of a second preferredembodiment of a resistance regulator for a magnetic brake according tothis invention, including a modified assembly of a side mark unit and aside indicator; and

[0025]FIG. 14 is a partly exploded perspective view of a third preferredembodiment of a resistance regulator for a magnetic brake according tothis invention, illustrating another modified assembly of a side markunit and a side indicator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Referring to FIGS. 4, 5 and 6, a first preferred embodiment of aresistance regulator according to this invention is associated with amagnetic brake shown in FIG. 8, and is shown to include a base 20, arotating shaft unit 30, a regulator body 40, a rotary knob 50, a rotarycap 60, and a ring plate 70.

[0027] The base 20 has an annular chamber 21, a fixed post 22 thatextends upwardly therefrom and that is formed with a threaded hole 221,and a notch 23.

[0028] The rotating shaft unit 30 includes a hollow shaft body 31 thatis sleeved rotatably on the post 22 of the base 20, a reel 32 that issleeved fixedly on the shaft body 31, and a pull rope 33 that isfastened to the reel 32 at one end and that is coupled with the brakeshown in FIG. 8 in a known manner at another end so as to be biased tounwind from the reel 32. The pull rope 33 extends outwardly from thebase 20 via the notch 23. A rotary ring 34 is disposed fixedly aroundthe shaft body 31 above the reel 32, and has an outer surface, which isformed with a deep-colored area 35 and a light-colored area 35′. In thisembodiment, the deep-colored area 35 is deep red. A side indicator isdisposed on the outer surface of the rotary ring 34, and is configuredas a vertical line unit 35″ that is defined between the deep-coloredarea 35 and the light-colored area 35′. The shaft body 31 has arectangular upper end 36.

[0029] The regulator body 40 is shaped as a hollow cylinder, andincludes an open lower end, a top wall 40′, a surrounding wall 40″extending downwardly from a periphery of the top wall 40′, and anelongated circumferentially extending window 41 formed in thesurrounding wall 40″. The surrounding wall 40″ is disposed around therotating shaft unit 30, and has a lower end that is fixed to the base 20by known high-frequency welding techniques. A resistance-designatingside mark unit 42 is disposed on an outer surface of the surroundingwall 40″, and includes two small-resistance marks and sixlarge-resistance marks. The small-resistance and large-resistance marksare located immediately over the window 41. The small-resistance marksare configured as two numerals “1”, “2″. The large-resistance marks areconfigured as six numerals “3” to “8”, each adjacent pair of which arespaced apart from each other at a distance that is smaller than thedistances between the numerals “1” and “2” and between the numerals “2”and “3”. The numerals “1” to “8” represent different resistances thatincrease in magnitude from “1” to “8”, respectively. A transparentshield 43 is fixed to the surrounding wall 40″ so as to cover the window41. A minus mark “−” and a plus mark “+” are indicated on the outersurface of the surrounding wall 40″, and are located below and adjacentto the ends of the window 41. The top wall 401 is formed with twodiametrically opposed restricting cavities 44, each of which receives aspring 45 and a ball 46 in such a manner the ball 46 is biased by thespring 45 to project partially and upwardly therefrom.

[0030] The rotary knob 50 includes a peripheral piece 501 that is formedwith an external spline portion 51, and a central piece 52 that is fixedto the base 20 by means of a lock bolt 53, which extends through acentral hole 521 in the central piece 52 to engage the threaded hole 221in the post 22. The peripheral piece 50′ is sleeved rotatably on thecentral piece 52. A resistance-designating top mark unit 54 is disposedalong a periphery of a top surface of the central piece 52, and includestwo small-resistance marks and six equidistant large-resistance marks,which are configured as numerals “1” to “8”. In the top mark unit 54,each adjacent pair of the numerals “3” to “8” are spaced apart from eachother at a distance that is smaller than both the distances between thenumerals “1” and “2” and between the numerals “2” and “3”. The top markunit 54 further includes a minus mark “−” 54″ that is disposed in frontof the numeral “1” and that indicates the turning direction fordecreasing the resistance during resistance adjustment, and a plus mark“+” 54″ that is disposed behind the numeral “8” and that indicates theturning direction for increasing the resistance during resistanceadjustment. A top indicator 55 is disposed on a top surface of theperipheral piece 50′, and is configured as a triangular mark.

[0031] The rotary cap 60 is sleeved on the rotary knob 50, and isconstructed as a hollow cylinder that has an open lower end, atransparent top wall 61, and an internal spline portion 62 that engagesthe external spline portion 51, thereby permitting synchronous rotationof the rotary cap 60 and the peripheral piece 50′.

[0032] The ring plate 70 is disposed between the regulator body 40 andthe peripheral piece 50′, and has a peripheral portion with twopositioning sets, each of which includes a zero-resistance positioninghole 71 that corresponds to the numerals “1” of the side and top markunits 42, 54, a first positioning unit that is shaped as a circular hole72 and that corresponds to the numerals “2” of the side and top markunits 42, 54, six second positioning units that form cooperatively aslot 73 and that correspond respectively to the numerals “3” to “8” ofthe side and top mark units 42, 54, and a maximum-resistance designatinghole 74. Each of the ring plate 70 and the peripheral piece 50′ has arectangular hole 75, 56 (see FIG. 6), which engages fittingly therectangular upper end 36 of the shaft body 31, thereby permittingsynchronous rotation of the ring plate 70 and the peripheral piece 50′with the shaft body 31.

[0033] Referring to FIG. 7, the slot 73 has two closed ends, andalternate wide and narrow portions 731, 732. Each of the wide portions731 is generally oval. Each adjacent pair of the wide portions 731 arespaced apart angularly from each other at an angle of about 12°. Theholes 71 and 72 are spaced apart angularly from each other at an angleof about 45°. The hole 72 is spaced apart angularly from a leading oneof the wide portions 731 at an angle of about 21°.

[0034]FIG. 8 shows a flywheel brake assembly that is associated with theresistance regulator of this invention and that is coupled with the pullrope 33 (see FIG. 4) in a known manner. The flywheel brake assemblyincludes a rotating shaft 1″, a flywheel 2″, an aluminum ring 3″, twomounting plates 4″, and several magnets 5″.

[0035] Referring to FIGS. 4, 8, 9 and 10, when the rotary cap 60 isrotated so as to move the vertical line unit 35″ from the numeral “1” ofthe side mark unit 42 to the numeral “2”, the magnets 5″ move toward aninner surface of the flywheel 2″ by a distance (L1). When the verticalline 35″ moves from the numeral “2” to the numeral “3”, the magnets 5″move toward the inner surface of the flywheel 2″ by a distance (L2) thatis smaller than the distance (L1). When the vertical line 35″, movesbetween any adjacent pair of the numerals “3” to “8”, the magnets 5″move relative to the flywheel 2″ by a distance (L3) that is smaller thanthe distance (L2). Because the distances (L1), (L2) are larger than thedistance (L3), there is no need for high precision during themanufacture and assembly of the magnetic brake. Note that although thereare two small-resistance marks on each of the side and top mark units42, 54, one small-resistance mark is sufficient to achieve the object ofthis invention with respect to the manufacturing precision of the brake.

[0036] In FIGS. 11 and 12, the resistance regulator is adjusted to asecond resistance, where the vertical line unit 35″ is aligned with thenumeral “2” of the side mark unit 42 and where the top indicator 55 isaligned with the numeral “2” of the top mark unit 54. Because thedeep-colored area 35 is conspicuous in the window 41, a selected one ofthe numerals “1”, “2”, “3”, “4”, “5”, “6”, “7”, “8” can be read easily.

[0037]FIG. 13 shows a second preferred embodiment of a resistanceregulator according to this invention, which is similar to the firstpreferred embodiment in construction except for the position and thecolor of the side mark unit 42′. In this embodiment, the side mark unit42′ is indicated on the transparent shield 43′, and is formed from awhite colorant, which is conspicuous in the deep-colored area 35A.

[0038]FIG. 14 shows a third preferred embodiment of a resistanceregulator according to this invention, which is similar to the secondpreferred embodiment in construction except for the side indicator 35A.In this embodiment, the side indicator 35A is configured as adark-colored area that is disposed on the outer surface of the rotaryring 34′ between two light-colored areas 35B and that is movable in thewindow 41′ in a longitudinal direction of the window 41′. In thisembodiment, the side indicator 35A is dark red, and is sized such thatonly the selected one of the numerals “1”, “2”, “3”, “4”, “5”, “6”, “7”,“8” can be disposed therein.

[0039] With this invention thus explained, it is apparent the numerousmodifications and variations can be made without departing from thescope and spirit of this invention. It is therefore intended that thisinvention be limited only as indicated in the appended claims.

I claim:
 1. A resistance regulator for a magnetic brake, said regulator comprising: a base with a fixed post extending upwardly therefrom; a rotating shaft unit including a hollow shaft body sleeved rotatably on said post, a reel sleeved fixedly on said shaft body, a pull rope wound around said reel and having one end that is fastened to said reel, and another end that is adapted to be coupled with the brake in such a manner that said pull rope is biased to unwind from said reel, and a side indicator disposed fixedly on said shaft body and located above said reel so as to rotate about said shaft body; a regulator body fixed on said base and including a surrounding wall disposed around said rotating shaft unit, a resistance-designating side mark unit disposed on said surrounding wall and having a small-resistance mark and a plurality of equidistant large-resistance marks which represent different resistance resistances that are larger than that of said small-resistance mark of said side mark unit, said small-resistance mark and said large-resistance marks of said side mark unit being arranged circumferentially on said surrounding wall, each adjacent pair of said large-resistance marks of said side mark unit being spaced apart from each other at a distance that is smaller than a distance between said small-resistance mark of said side mark unit and a leading one of said large-resistance marks of said side mark unit, said side indicator being directed toward a selected one of said large-resistance and small-resistance marks of said side mark unit so as to be adapted to indicate a resistance of the brake, and a top wall with a spring-biased ball that is biased to project upwardly and partially therefrom; a rotary knob unit including a central piece mounted fixedly on said post of said base and having a top surface, a resistance-designating top mark unit disposed on said top surface of said central piece and having a small-resistance mark and a plurality of equidistant large-resistance marks which represent different resistances that are larger than that of said small-resistance mark of said top mark unit, said small-resistance mark and said large-resistance marks of said top mark unit being arranged circumferentially on said top surface of said central piece and corresponding respectively to said small-resistance mark and said large-resistance marks of said side mark unit, each adjacent pair of said large-resistance marks of said top mark unit being spaced apart from each other at a distance that is smaller than a distance between said small-resistance mark of said top mark unit and a leading one of said large-resistance marks of said top mark unit, a peripheral piece sleeved rotatably on said central piece and connected fixedly to said shaft body of said rotating shaft unit, said peripheral piece having a top surface, and a top indicator fixed on said top surface of said peripheral piece and directed toward a selected one of said small-resistance and large-resistance marks of said top mark unit; and a ring plate sleeved fixedly on said shaft body of said rotating shaft unit and having a first positioning unit and a plurality of second positioning units that correspond respectively to said small-resistance and large-resistance marks of said side and top mark units, said peripheral piece of said rotary knob being rotatable relative to said base and said regulator body so as to engage said spring-biased ball of said regulator body with a selected one of said first and second positioning units in said ring plate, thereby aligning said top and side indicators with corresponding ones of said small-resistance and large-resistance marks of said top and side mark units.
 2. The resistance regulator as claimed in claim 1, further comprising a rotary cap, which is shaped as a hollow cylinder that has an open lower end and a transparent upper end wall and which is disposed around said peripheral piece, one of said peripheral piece and said rotary cap having an internal spline portion, the other one of said peripheral piece and said rotary cap having an external spline portion that engages said internal spline portion, thereby permitting synchronous rotation of said peripheral piece and said rotary cap.
 3. The resistance regulator as claimed in claim 1, wherein each of said peripheral piece and said ring plate has a rectangular hole, said shaft body of said rotating shaft unit having a rectangular upper end that engages fittingly said rectangular holes in said peripheral piece and said ring plate, thereby preventing rotation of said peripheral piece and said ring plate relative to said shaft body.
 4. The resistance regulator as claimed in claim 1, wherein said surrounding wall includes an elongated circumferentially extending window that is formed therethin, said rotating shaft unit including a rotary ring which is disposed fixedly around said shaft body and which has an outer surface that has a light-colored area and a deep-colored area, said light-colored area and said deep-colored area defining a vertical line unit therebetween that constitutes said side indicator and that is movable in said window in said surrounding wall in a longitudinal direction of said window when said peripheral piece rotates relative to said central piece, said surrounding wall having an outer surface, said large-resistance and small-resistance marks of said side mark unit being indicated on said outer surface of said surrounding wall and being located immediately over said window.
 5. The resistance regulator as claimed in claim 4, wherein said regulator body further includes a transparent shield, which is fixed on said surrounding wall and which covers said window in said surrounding wall.
 6. The resistance regulator as claimed in claim 4, wherein said ring plate further includes a leading positioning unit that is shaped as a circular hole, and a slot that has two closed ends and a plurality of alternate wide and narrow portions, said wide portions being wider than said narrow portions and constituting said second positioning units, respectively, said first positioning unit being located between said leading positioning unit and said second positioning units and being spaced apart angularly from said leading positioning unit at an angle of about 45°, each of said wide portions of said slots being generally oval, a leading one of said wide portions being spaced apart angularly from said first positioning unit at an angle of about 21°, each adjacent pair of said wide portions being spaced apart angularly from each other at an angle of about 12°.
 7. The resistance regulator as claimed in claim 1, wherein said surrounding wall includes an elongated circumferentially extending window that is formed therein, and a transparent shield that is fixed to said surrounding wall and that covers said window, said rotating shaft unit including a rotary ring which is disposed fixedly around said shaft body and which has an outer surface that is formed with a deep-colored area and a light-colored area, said deep-colored area and said light-colored area defining a vertical line unit therebetween that constitutes said side indicator and that is movable in said window in said surrounding wall in a longitudinal direction of said window when said peripheral piece rotates relative to said central piece, each of said large-resistance and small-resistance marks of said side mark unit being formed from a white colorant and being indicated on said transparent shield.
 8. The resistance regulator as claimed in claim 1, wherein said surrounding wall includes an elongated circumferentially extending window, which is formed therethin and which has two closed ends, and a transparent shield that is fixed to said outer surface of said surrounding wall and that covers said window, said rotating shaft unit including a rotary ring that is disposed fixedly around said shaft body and that has an outer surface, said side indicator being configured as a dark-colored area that is indicated on said outer surface of said rotary ring, said dark-colored area being movable in said window in said surrounding wall in a longitudinal direction of said window when said peripheral piece rotates relative to said central piece, so as to move a selected one of said large-resistance and small-resistance marks of said side mark unit into said dark-colored area. 